Polyimide finds wide use in a variety of industrial fields because of its excellent heat resistance and mechanical characteristics. In actual applications of polyimide, modification of its surface properties, such as adhesiveness and wettability, is of frequent concern. Surface modification methods proposed for polyimide films include corona discharge treatment, plasma treatment, sand blasting, and chemical etching. For example, Patent Document 1 discloses a discharge treatment of the surface of a polyimide film. Patent Document 2 discloses a polyimide film laminated with a metal foil prepared by using a vacuum plasma treated polyimide film. Patent Document 3 proposes surface modification by applying a surface modifier to a polyimide film.
Patent Document 4 proposes a polyimide film having a specific chemical composition thereby exhibiting improved adhesive strength.
Patent Document 1: JP 5-1160A
Patent Document 2: JP 2005-125721A
Patent Document 3: JP 2003-192811 A
Patent Document 4: JP 2005-146074A